DE202016008930U1 - Partial unicompartmental system for partial knee replacement - Google Patents

Abstract

Partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, comprising:
a femur component (120) configured to restore at least a portion of a femoral condyle, the femur component having a first region (310) with a first radius of curvature and a second region (312) with a second radius of curvature, characterized in that the femur component further comprises a third region (314) with a third radius of curvature and in that the system further comprises:
a meniscus component (110) which is configured to be positioned between the femur component (120) and the natural tibia, the meniscus component (110) in the knee joint between the tibia and the femur component (120) floats and has a first position in the knee joint when in contact with the first region (310), a second position in the knee joint when in contact with the second region (312), and a third position in the Has knee joint when it is in contact with the third region (314).

Description

BACKGROUND

The present disclosure relates generally to medical prosthetic devices, systems, and methods. More particularly, in some instances, the present disclosure relates to prosthetic devices that replace at least some of the functionality of the natural meniscus and knee support surfaces. Each knee has two meniscus, a lateral meniscus and a medial meniscus. Each meniscus is a crescent-shaped fibrous cartilaginous tissue attached to the tibia by an anterior and posterior horn. Damage to the meniscus can cause pain and arthritis. Furthermore, cartilage on the contact surfaces of the tibia and the thigh bone can be damaged, which leads to additional pain and damage to the meniscus. Accordingly, it is common practice to have a total knee replacement performed in many patients with damaged knee cartilage. Alternatively, if the damaged cartilage is confined to one side of the knee, a unicompartmental knee replacement procedure can be performed in which the thigh and shin bones are milled and implants are placed in both bones to perform the load-bearing function of the knee. Even if cartilage is damaged from only one of the bone surfaces, both cartilage surfaces are removed and replaced with an artificial support surface.

There is a need for less traumatizing and bone preserving devices that can meet resilience and knee function requirements over a spectrum of knee movements. While existing devices, systems, and methods have attempted to address these issues, they are unsatisfactory in all respects. Accordingly, there is a need for improved devices, systems, and methods in accordance with the present disclosure.

SUMMARY

In one embodiment, a partial unicompartmental knee replacement system is provided. The partial unicompartmental knee replacement system provides a system that allows only the affected joint surface to be treated, while the intact cartilage bearing surfaces on the opposite areas of the joint are preserved. In one form, the system comprises a femur component configured to restore at least a portion of a femoral condyle, the femur component having a first bearing surface with a first radius of curvature, a second bearing surface with a second radius of curvature, and a third bearing surface with a third Has a radius of curvature and a meniscus component that is configured to be positioned between the femur component and the natural tibia. The meniscus component floats in the knee joint between the natural tibia and the femur component and occupies a first position in the knee joint on contact with the first area, a second position in the knee joint on contact with the second area and a third position in the Knee joint in contact with the third area. In one aspect, the first position is offset in the direction of rotation with respect to the second and / or third position. In a further aspect, the first position is offset in the longitudinal direction with respect to the second and / or third positions. In yet another aspect, the first position is laterally offset with respect to the second and / or third position. In at least one configuration, the first radius of curvature is different from the third radius of curvature.

In another configuration, a tibial support component can be implanted to replace the natural tibial support surface. The shin support component has a multi-surface support surface with a convex support section. A free-floating meniscal device has a lower surface for engagement with the tibial support component and an upper surface for engagement with the natural femur support surface. The meniscus device floats between a variety of anterior to posterior positions and rotational positions in response to movement of the femur and its engagement with the multi-faceted support surface of the tibial support component.

In another embodiment, a method for replacing the function of a cartilage support surface and meniscus in a joint is provided. The method of replacing the support surface includes removing the cartilage surface from a bone in the joint and implanting a replacement support component. The method of replacing the meniscus function in a joint includes removing a portion of a meniscus within the joint and obtaining a remnant meniscus, then inserting a floating meniscal replacement implant into the joint and engaging the Meniscus replacement implant with the meniscus remnant such that the meniscus replacement implant is at least partially retained within the joint by the meniscus remnant. In another aspect, the meniscal replacement implant includes a retention channel within the sidewall of the implant, and the method of engaging the meniscal replacement implant with the meniscal remnant includes aligning the retention channel with the meniscus remnant. In yet another feature, the retention channel is a retention channel formed in a posterior portion of a knee meniscus replacement implant, and the engaging includes aligning the retention channel with a posterior portion of the meniscal remnant. In yet another aspect, engaging includes suturing a portion of the replacement meniscal implant to a portion of the remnant meniscal or to the tissue of the joint capsule adjacent the joint.

Figure list

• 1 eine schematische perspektivische Ansicht eines rechten Kniegelenks mit einem unikompartimentellen Knieersatz gemäß einem Aspekt der vorliegenden Erfindung ist.
• 2 eine schematische, Teil-Explosions-, perspektivische Ansicht eines linken Kniegelenks mit einem unikompartimentellen Knieersatz gemäß einem Aspekt der vorliegenden Erfindung ist.
• 3 eine Seitenansicht einer Oberschenkelknochen-Auflagekomponente ist.
• 4 eine schematische perspektivische Ansicht einer alternativen Oberschenkelknochen-Auflagekomponente ist.
• 5 eine Vorderansicht eines partiellen unikompartimentellen Knieersatzsystems gemäß einer Ausführungsform ist.
• 6 eine perspektivische Ansicht einer prothetischen Meniskus-Komponente ist.
• 7 ein Querschnitt der Meniskus-Komponente von 6 ist.
• 8 eine perspektivische Ansicht eines Knies ist, die eine implantierte Meniskus-Vorrichtung in einer Reihe von Positionen darstellt.
• 9A-9C ein implantiertes partielles unikompartimentelles Knieersatzsystem gemäß der vorliegenden Erfindung veranschaulichen, das mit dem Knie über eine Reihe von Winkeln ein Gelenk bildet.
• 10A-10C die Drehposition der Meniskus-Komponente des Systems in den 9A-9C veranschaulichen.
• 11A und 11B eine Meniskus-Vorrichtung mit Halteschlaufen veranschaulichen.
• 12A-12C schematische Darstellungen eines prothetischen partiellen unikompartimentellen Knieersatzsystems einer weiteren Ausführungsform sind, die dem Kniegelenk zugeordnet sind.
• 13A-13C verschiedene Ansichten des Systems von 12A veranschaulichen.
• 14A-15C verschiedene Ansichten der Schienbeinkopf-Auflagekomponente veranschaulichen, die dem System von 12A zugeordnet ist.
• 16A-16D ein implantiertes partielles unikompartimentelles Knieersatzsystem gemäß 12A veranschaulichen, das mit dem Knie über eine Reihe von Winkeln ein Gelenk bildet.
• 17A-17 C die Drehposition der Meniskus-Komponente des in den 16A-16D gezeigten Systems veranschaulichen.

Other features and advantages of the present disclosure will become apparent from the following detailed description of embodiments of the disclosure with reference to the accompanying drawings, of which:

• 1 Figure 3 is a schematic perspective view of a right knee joint having a unicompartmental knee replacement in accordance with an aspect of the present invention.
• 2 Figure 13 is a schematic, partially exploded, perspective view of a left knee joint with a unicompartmental knee replacement in accordance with an aspect of the present invention.
• 3 Figure 3 is a side view of a femur support component.
• 4th Figure 4 is a schematic perspective view of an alternative femur support component.
• 5 Figure 3 is a front view of a partial unicompartmental knee replacement system in accordance with an embodiment.
• 6th Figure 3 is a perspective view of a prosthetic meniscal component.
• 7th a cross-section of the meniscus component of FIG 6th is.
• 8th Figure 3 is a perspective view of a knee depicting an implanted meniscal device in a series of positions.
• 9A-9C Illustrate an implanted partial unicompartmental knee replacement system in accordance with the present invention that articulates the knee through a series of angles.
• 10A-10C the rotational position of the meniscus component of the system in the 9A-9C illustrate.
• 11A and 11B illustrate a meniscus device with retaining loops.
• 12A-12C are schematic representations of a prosthetic partial unicompartmental knee replacement system of a further embodiment, which are assigned to the knee joint.
• 13A-13C different views of the system from 12A illustrate.
• 14A-15C illustrate various views of the tibial head support component that make up the system of FIG 12A assigned.
• 16A-16D an implanted partial unicompartmental knee replacement system according to 12A illustrate how the knee articulates through a number of angles.
• 17A-17 C the rotational position of the meniscus component of the 16A-16D system shown.

Detailed description

To assist in understanding the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the illustrated embodiments. It should be understood, however, that no limitation on the scope of the disclosure is intended. Any and all changes or modifications to the devices, instruments and / or methods described, as well as any further application of the principles of the present disclosure that would be obvious to a person skilled in the art, are embraced by the present disclosure, even if they are not expressly discussed herein. Further, it is fully contemplated that the features, components, and / or steps described with respect to one embodiment may be combined with the features, components, and / or steps described with respect to other embodiments of the present disclosure are described.

With reference to 1 is a right knee joint between the thigh bones (femur) F. and shin (tibia) T shown. A partial unicompartmental knee replacement (PUKR) system 100 was implanted in the medial compartment of the knee. As will be explained in more detail below, the PUKR system is only a partial, unicompartmental knee replacement, since it leaves at least one of the natural contact surfaces of the knee intact. In the illustrated embodiment, an artificial femur support surface was used 120 implanted on the femur to attach to a prosthetic meniscus device 110 lie to come, which in turn is due to the native Tibial head rests. An upper surface of the prosthetic meniscus device 110 is in contact with the artificial femur support surface 120 , and a lower surface of the prosthetic meniscus device 110 is in contact with the natural tibia contact surface. 2 Figure 3 illustrates that a system similar to that of the prosthetic meniscus device can be implanted in the left knee 110 and the femur support surface 120 includes. The meniscus device 110 is adjacent to a ligament within the knee joint 130 positioned, such as a coronary or meniscotibial ligament, a meniscofemoral ligament, and / or a transverse ligament. For purposes of illustration, the prosthetic system is described in connection with a left knee, medial meniscus, and pad replacement in the following drawings. However, corresponding embodiments are used to replace any of the other knee pads and meniscus, such as the medial meniscus of the right knee, the lateral meniscus of the left knee, and / or the lateral meniscus of the right knee. The size, shape, thickness, material properties and / or other properties of the prosthetic device can be designed for each specific application.

3 Figure 12 shows a femur support component 120 . The femur support component includes a first support area 310 with a first larger radius, a second support area 312 with a second radius that is smaller than the first radius, and a third support area 314 with a third radius that is smaller than the second radius, and a fourth bearing surface 316 . Although a femur component is shown with multiple radii, it is possible for the femur component to have a bearing surface with a single continuous bearing surface with a single radius or a number of radii less or more than the four radii shown in FIG 3 are shown. One or more radii of the femur support component can be used 120 be chosen so that they replicate the shape of a natural thigh bone. The femur support surface is established by inserting the pins 330 and 332 held in prepared bone holes in the bone. While two pins are shown, it will be understood that any number of anchoring tabs on the back of the femur component can be used to provide a firm anchorage to the bone. The femur component 120 replaces the patient's femur support surface on the side of the knee where it is used. For example, the femur component 120 can be implanted to repair a defect in either the medial condyle or the lateral condyle. An alternative femur support component 350 is in 4th shown. The femur support component 350 has a smaller bearing surface that is intended to replace a relatively small defect in the natural femur bearing surface, so that the surface 352 reproduces the natural shape of the patient's support surface. As in 5 Shown may be the femur component 350 in the knee using the pen 356 can be implanted to maintain their position in conjunction with a corresponding prosthetic meniscal device in accordance with the present disclosure. The femur component can be formed from any suitable biocompatible material including, but not limited to, cobalt chrome.

In the 6th and 7th there is shown a prosthetic device having features similar to an earlier design shown in U.S. Patent No. 8,361,147 is set out, which is hereby incorporated by reference in its entirety. In general, the prosthetic device is designed to replace the function of a meniscus in a partial unicompartmental knee replacement system and is designed to cooperate with the replacement support surface in order to move the meniscus component into different engagement positions with the opposite natural support surface. The prosthetic meniscus can be implanted to replace the lateral meniscus or the medial meniscus. Here, a prosthetic lateral meniscus is arranged between and in contact with an artificial lateral femur support surface and the natural lateral tibial head. Similarly, a prosthetic medial meniscus is disposed between and in contact with an artificial medial femur support surface and the natural medial tibial head. As described below, the prosthetic meniscus device can also be used with a natural femur support surface and an artificial tibial support surface. The mobility of the meniscus device mimics a natural meniscus and naturally distributes loading stresses over the remaining natural bearing surface when used with a partial unicompartmental knee replacement system. The meniscus device is sized to cooperate with a specifically sized prosthetic femur component. Thus, it is contemplated that the femur component may be adapted to at least one meniscus device and that multiple adapted pairs of implants may be available for treating patients with different knee anatomies and sizes.

The prosthetic meniscus includes an outer body portion 108 and a central body portion 110 . In principle, the outer body section 108 an increased thickness and height relative to the central body portion 110 on. In some cases, the outer body portion has 108 a thickness between 5 mm and 15 mm. In some cases, the central body section has 110 a thickness between 0.5 mm and 5 mm. In a particular embodiment, the outer body portion has 108 a maximum thickness of about 10 mm and the central body portion 110 has a maximum thickness of approximately 2 mm. In some cases, the height or thickness of the outer body portion will vary 108 along the perimeter of the prosthetic device. In some embodiments, this includes variations in the height or thickness of the outer body portion 108 chosen so that they match the anatomical conditions of the patient. Similarly, the height or thickness of the central body portion varies 110 in some embodiments, across the prosthetic device. Again, the variations are in the height or thickness of the central body portion 110 chosen so that in some embodiments they match the anatomical conditions of the patient. In some embodiments, the prosthetic device 100 inserted into an insertion assembly and then loaded, stretched, moved and / or otherwise transferred into an implantation assembly. In some embodiments, the transformation between the deployment assembly and the implantation assembly is accomplished by loading the prosthetic device 100 facilitated. In such embodiments, the variations in height or thickness of the outer and central body sections 108 , 110 is chosen to accommodate the deformation or transformation between the insertion assembly and the implantation assembly.

In the illustrated embodiment, the prosthetic device is designed for use without a fastener or fixture that would penetrate adjacent bone and / or soft tissue to hold the prosthetic device in place. Rather, it is the prosthetic device 100 designed to "swim" within the knee joint without fasteners penetrating such bone and / or soft tissue or otherwise rigidly attached to the thigh, the artificial femur support component, the artificial tibia support component, or the shin and / or surrounding soft tissue to be attached. For this purpose is the outer body section 108 the prosthetic device 100 shaped and dimensioned to prevent the prosthetic device from accidentally popping out of the knee joint. While bone must be removed to implant a femoral or tibial support component, the meniscus prosthetic device is implanted in a patient without permanent damage to the patient's undamaged tibia or any other bone and / or soft tissue structure (s) which, in some embodiments, are interfered with by the prosthetic device. In some cases the prosthetic device will 100 implanted to alleviate the patient's knee problems while avoiding permanent destruction of the patient's anatomy, such as B. cutting or reaming a large opening in the tibia. In such cases the prosthetic device can 100 subsequently removed and replaced with another prosthetic device or treatment without adversely affecting subsequent treatment. In other instances where the tibial support surface remains intact, a tibial support component can be implanted prior to placement of the prosthetic meniscal device.

To this end, the outer body portion comprises 108 of the prosthetic device has a first section 112 and a second section or bridge 114 . In some embodiments, the first portion corresponds 112 essentially in the shape of a natural meniscus. In some embodiments, the outer body portion has 108 a semi-ellipsoidal shape. The first section extends accordingly 112 around much of the outer body portion 108 . The bridge 114 connects the two ends of the first section 112 . Thus the bridge extends 114 when the prosthetic device is adapted for use as a medial meniscus device, along the lateral side of the device. When the prosthetic device is configured for use as a lateral meniscus device, the bridge extends 114 along the medial side of the device. Accordingly, the outer body portion surrounds 108 - the one from the first section 112 and the bridge 114 and an increased thickness relative to the central body portion 110 having the central body portion 110 complete and serves to limit movement of the prosthetic device after implantation. That is, the increased thickness of the outer body portion 108 along with the contact pressure on the prosthetic device to be positioned between the femur component and the tibia prevents the prosthetic device from moving outside of the desired range of positions within the knee joint.

The height or thickness of the bridge component 114 is based on the size of the femur notch and the distance to the cruciate ligaments in some embodiments. In some embodiments, the bridge 114 a maximum height or thickness that is between ¼ and ¾ of the maximum height or thickness of the first section 112 of the outer body section 108 lies. In some embodiments, the size and shape of the bridge 114 chosen so that an optimal pressure distribution on the tibia head is achieved in order to simulate the pressure distribution of a healthy natural meniscus. The bridge 114 and more generally the outer body portion 108 are geometrically characterized by anterior, posterior, lateral-anterior, mid-lateral and lateral-posterior angles and heights as well as sagittal and coronal radii of curvature. Furthermore, the outer body portion 108 and the central body section 110 Shaped and sized to fit the prosthetic device 100 is self-centering. That is, the shape and size of the prosthetic meniscus device itself promotes the prosthetic device to position or align with a desired orientation within the knee joint based on the position of the prosthetic femur support component. Accordingly, as the meniscal prosthetic device moves through a range of positions within the knee joint, it naturally reverses due to the shape and size of the outer and central body portions 108 , 110 back to the desired orientation. In some embodiments, the outer body portion and in particular the bridge acts 114 as a physical barrier that limits movement of the prosthetic device caused by joint reaction forces. The shape of the associated femoral or tibial support component that cooperates with the self-centering or self-aligning mechanism, along with the ability of the prosthetic device to move within the knee joint, results in an improved position of the prosthetic device 110 during typical walking cycles (e.g. flexion-extension angles from 0 ° to 20 ° or "stepping on the heel" to "lifting the toes"). The result is the prosthetic device 110 has a load pressure distribution similar to that of a natural meniscus.

The central body section 110 defines a top surface 116 and a lower surface 118 . The top and bottom surfaces 116 , 118 are both loaded surfaces. In particular, the top and bottom surfaces are 116 , 118 designed so that they are each movably engaged with a prosthetic femur support surface and a natural tibial head or, conversely, with a natural femur support surface and an artificial tibial head. In this regard, the prosthetic device 110 move and rotate within a range in relation to the femur and / or tibia. In some cases, displacement is possible in both the anterior-posterior and medial-lateral directions. In some embodiments, the top surface includes 116 both a vertical and a horizontal surface. To this end, the top surface points 116 in some embodiments, a concave surface that defines vertical and horizontal surfaces. The thickness of the central body portion 110 between the top surface 116 and the lower surface 118 supports the load sharing ability of the component while increasing the height of the top surface 116 when they move outward toward the outer body portion 108 extends, defines the horizontal surface of the component. Similarly, in some embodiments, includes the bottom surface 118 both vertical and horizontal components. In particular, the lower surface 118 in some embodiments, a convex surface. The thickness of the central body portion 110 between the top surface 116 and the lower surface 118 determines the load-distributing ability of the component, while the decreased height of the lower surface 116 when they move outward toward the outer body portion 108 extends that defines the horizontal component. In some embodiments, these are the top surface 116 and / or the lower surface 118 shaped so that the prosthetic device 100 is biased towards a neutral position in the knee. For example, the curved profiles are the top surface 116 and / or the lower surface 118 shaped in such a way that the interaction between the surfaces and the prosthetic surface component favors a certain orientation of the implant relative to the surfaces. This enables the prosthetic device 100 is self-centering or self-aligning as discussed below.

Referring to the 7th , there is a schematic cross-sectional view of the prosthetic device 110 along an anterior to posterior cutting line between the anterior end 113 and the posterior end 115 shown. The central body 110 is made of pre-tensioned fibers wound around the core 124 reinforced to prevent external deformation while allowing internal flexibility. As shown, the anterior area 113 of the outer body section 108 an anterior height or thickness 160 on. The anterior height or thickness is 160 of the anterior end 113 between about 4 mm and could, immediately adjacent to the bridge structure 114 , be about 15 mm, and is, in some Cases, between about 5.7 mm and about 9.3 mm. In the present embodiment, the anterior height or thickness is 160 of the anterior end 113 about 7.8 mm. In a smaller embodiment, the anterior height or thickness is 160 about 5.7 mm. In a larger configuration, the anterior height or thickness is 160 about 9.3 mm. The posterior height or thickness 162 of the posterior end 114 is between about 4 mm and could, immediately adjacent to the bridge structure 114 , about 20 mm and, in some cases, between about 7.7 mm and about 12.7 mm. In the present embodiment, the posterior height or thickness is 162 of the posterior end 115 about 9.0 mm. In a smaller embodiment, the posterior height or thickness is 162 about 7.7 mm. In a larger configuration, the posterior height or thickness is 162 approximately 12.7 mm.

The anterior portion of the upper surface of the anterior region 113 has an anterior radius of curvature 164 on. The anterior radius of curvature is 164 between about 10 mm and about 100 mm and, in some cases, between about 23.0 mm and about 33.1 mm. In the present embodiment, the radius of curvature is 164 about 72 mm. In another embodiment, the radius of curvature is 164 about 28 mm. In a smaller embodiment, the radius of curvature is 164 about 23 mm. In a larger embodiment, the radius of curvature is 164 approximately 33.1 mm. The posterior portion of the upper surface of the posterior area 115 has a posterior radius of curvature 166 on. The posterior radius of curvature is 166 between about 5 mm and about 70 mm and, in some cases, between about 15.2 mm and about 24.2 mm. In the present embodiment, the radius of curvature is 166 about 30 mm. In a smaller embodiment, the radius of curvature is 166 about 15.2 mm. In a larger embodiment, the radius of curvature is 166 approximately 24.2 mm.

The anterior area also extends 113 the upper surface generally at an anterior angle 168 with respect to an axis 170 which extends substantially perpendicular to a plane generally through the prosthetic device 100 is defined as shown. The anterior angle 168 is between about 45 degrees and about 75 degrees and, in some cases, is between about 62 degrees and about 68 degrees. In the present embodiment, the angle is 168 about 65 degrees. In a smaller embodiment, the angle is 168 about 62 degrees. In a larger embodiment, the angle is approximately 68 degrees. The posterior area 115 the upper surface extends generally at a posterior angle 172 with respect to an axis 174 which extends substantially perpendicular to a plane generally through the prosthetic device 100 is defined as shown. The posterior angle 172 is between about 35 degrees and about 70 degrees and, in some cases, is between about 55 degrees and about 61 degrees. In the present embodiment, the angle is 172 about 58 degrees. In a smaller embodiment, the angle is 172 about 50 degrees. In a larger embodiment, the angle is 172 about 65 degrees.

The central body section 110 has a height or thickness 176 between the upper articular surface 116 and the lower articular surface 118 on. In some configurations, the height or thickness is 176 the minimum thickness of the central body portion 110 , and, in more specific configurations, the minimum thickness of the entire prosthetic device 100 . To do this, the height or thickness is 176 between about 1 mm and about 3 mm and in some cases is between about 1.2 mm and about 2.1 mm. In the present embodiment, the height or thickness is 176 about 1.5mm. In a smaller embodiment, the height or thickness is 176 about 1.2mm. In a larger embodiment, the height or thickness is 176 about 2.1 mm.

A variety of materials are suitable for use in making the prosthetic devices of the present disclosure. Medical grade polyurethane-based materials particularly suitable for use in the described embodiments include, but are not limited to, alone or in combination:

Bionate®, made by DSM, a polycarbonate urethane, is one of the most extensively tested biomaterials ever developed. Carbonate bonds adjacent to hydrocarbon groups give this family of materials oxidative stability, making these polymers attractive in applications where oxidation is a potential mode of degradation, such as in pacemaker leads, ventricular assist devices, catheters, stents, and many other biomedical devices. Polycarbonate urethanes were the first biomedical polyurethanes to be advertised for bio-stability. Bionate® polycarbonate urethane is a thermoplastic elastomer that is formed as a reaction product of a hydroxyl-terminated polycarbonate, an aromatic diisocyanate and a low molecular weight glycol, which is used as a chain extender. The results of extensive tests including histology, carcinogenicity, biostability and tripartite biocompatibility guide for medical devices verify the biocompatibility of the inexpensive material.

Another group of suitable materials are copolymers of silicone with polyurethanes, for example PurSil ™, a silicone-polyether urethane, and CarboSil ™, a silicone-polycarbonate-urethane. Silicones have long been known to be biostable and biocompatible in most implants, and often have the low hardness and modulus of elasticity useful for many device applications. Conventional silicone elastomers can have very high elongations at break, but only low to moderate tensile strengths. As a result, most biomedical silicone elastomers are not very hard. Another disadvantage of conventional silicone elastomers in device fabrication is the need for crosslinking to develop useful properties. Once crosslinked, the resulting thermoset silicone cannot be dissolved again or melted again. In contrast, conventional polyurethane elastomers are generally thermoplastic with excellent physical properties. Thermoplastic urethane elastomers (TPUs) combine high elongation and high tensile strength to form tough elastomers, albeit with fairly large modulus of elasticity. Aromatic polyether TPUs can have excellent flex life, tensile strengths greater than 5000 psi, and elongations at break greater than 700 percent. These materials are often used for continuous bending, chronic implants such as ventricular assist devices, intraortic balloons, and artificial cardiac components. TPUs can be easily processed by melting or dissolving the polymer to make it into useful shapes.

The prospect of combining the biocompatibility and biostability of conventional silicone elastomers with the processability and strength of TPUs is an attractive approach to what appears to be a near-ideal biomaterial. For example, it has been shown in the case of polyurethanes based on polycarbonate that the silicone copolymerization reduces the hydrolytic degradation of the carbonate bond, while in the case of polyether urethanes the covalently bound silicone appears to protect the polyether soft segment from oxidative degradation in vivo. DSM synthesized silicone-polyurethane copolymers by combining two processes described above: Copolymerization of silicone (PSX) together with organic (non-silicone) soft segments in the polymer backbone and use of surface-modifying end groups to terminate the copolymer chains.

Other applicable materials include PurSil ™ silicone-polyether-urethane and CarboSil ™ silicone-polycarbonate-urethane, which are true thermoplastic copolymers that contain silicone in the soft segment. These high-strength thermoplastic elastomers are produced by a multistage mass synthesis, whereby polydimethylsiloxane (PSX) is introduced into the polymeric soft segment together with polytetramethylene oxide (PTMO) (PurSil) or an aliphatic, hydroxyl-terminated polycarbonate (CarboSil). The hard segment consists of an aromatic diisocyanate, MDI, with a low molecular weight glycol chain extender. The copolymer chains are then terminated with silicone (or other) surface-modifying end groups. Aliphatic (AL) versions of these materials with a hard segment synthesized from an aliphatic diisocyanate are also available.

Many of these silicone urethanes exhibit desirable combinations of physical properties. For example, aromatic silicone polyether urethanes have a higher modulus of elasticity than conventional polyether urethanes at a certain Shore hardness - the greater the silicone content, the greater the modulus of elasticity (see properties of PurSil). Conversely, the aliphatic silicone polyether urethanes have a very low modulus of elasticity and a large elongation at break, which is typical for silicone homopolymers or even natural rubber (see properties of PurSil AL). These properties make these materials very attractive as high-performance substitutes for conventional cross-linked silicone rubber. In both the PTMO and PC families, some polymers have tensile strengths that are three to five times greater than that of traditional silicone biomaterials.

Further examples of suitable materials include surface modifying end groups (SMEs), which are surface-active oligomers that are covalently bonded to the base polymer during synthesis. SMEs - the silicone (S), sulfonate (SO), fluorocarbon ( F. ), Polyethylene oxide (P), and hydrocarbon (H) groups - control surface chemistry without affecting the bulk properties of the polymer. The result is that essential surface properties, such as thromboresistance, biostability and abrasion resistance, are permanently increased without additional treatments following production or any local coatings. This technology is applied to many DSM polymers.

SMEs provide a number of base polymers that can achieve a desired surface chemistry without the use of additives. Polyurethanes produced according to the DSM development process couple end groups to the main chain polymer via a terminal isocyanate group during the synthesis, not a hard segment. The additional mobility of end groups relative to the main chain facilitates the formation of uniform cover layers by the surface-active end blocks. The use of the surfactant end groups leaves the original polymer backbone intact so that the polymer retains strength and processability. The fact that essentially all polymer chains carry the surface-modifying moiety eliminates many of the potential problems associated with additives.

The SME approach also allows the introduction of mixed end groups into a single polymer. For example, the combination of hydrophobic and hydrophilic end groups gives the polymers amphipathic properties in which the balance of hydrophobicity to hydrophilicity can be controlled in a simple manner.

Other suitable materials manufactured by CARDIOTECH CTE include ChronoFlex® and Hydrothane ™.

ChronoFlex ®, polycarbonate-aromatic polyurethanes, belonging to the family of segmented bio-resistant polyurethane elastomers with medical quality, were specially developed by CardioTech International to overcome the in vivo formation of stress-induced microcracks.

HydroThane ™, hydrophilic thermoplastic polyurethanes, is a family of superabsorbent, thermoplastic polyurethane hydrogels with a water content ranging from 5 to 25% by weight. HydroThane ™ is available as a clear resin with a durometer hardness of 80A and 93 Shore A. offered. The outstanding properties of this family of materials are the ability to quickly absorb water, great tensile strength and high elasticity. The result is a polymer with lubricating properties and inherent bacterial resistance due to its exceptionally high water content on the surface. HydroThane ™ hydrophilic polyurethane resins are thermoplastic hydrogels and can be extruded or molded by conventional means. Conventional hydrogels, on the other hand, are thermosets and difficult to process.

Other suitable materials manufactured by THERMEDICS include Tecothante® (aromatic polyurethane based on polyether), Carbothane® (aliphatic polyurethane based on polycarbonate), Tecophilic® (aliphatic polyurethane based on polyether with high moisture absorption capacity) and Tecoplast® (aromatic polyurethane based on polyether). Tecothane® is a family of aromatic polyether-based TPUs that are available in a wide range of hardness levels, colors and radiation dampening properties. It is to be expected that Tecothane resins will show improved solvent resistance and improved biostability compared to Tecoflex resins with the same degrees of hardness. Carbothane® is a family of polycarbonate-based aliphatic TPUs that are available in a wide range of hardnesses, colors and radiation damping properties. It has been reported that this type of TPU has excellent oxidative stability, a property that can be equated with excellent long-term biostability. This family, like Tecoflex, is easy to work with and does not turn yellow with age. Tecophilic® is a family of aliphatic polyether-based TPUs that have been specially formulated to absorb equilibrium water contents of up to 150% by weight of the dry resin.

Additional materials of interest include Tecogel, a new element for the Tecophile family, a hydrogel made to absorb equilibrium water contents between 500% and 2000% by weight of the dry resin, and Tecoplast®, a family of aromatic TPU's Polyether based that are manufactured to produce robust injection molded components that have high levels of hardness and heat deflection temperatures.

Other potentially useful materials include four families of polyurethanes called Elast-Eon ™ available from AorTech Biomaterials.

Elast-Eon ™ 1, a polyhexamethylene oxide (PFMO), an aromatic polyurethane, is an improvement on conventional polyurethane in that it has a reduced number of susceptible chemical groups. Elast-Eon ™ 2, a siloxane-based macrodiol, an aromatic polyurethane, contains siloxane in the soft segment. Elast-Eon ™ 3, a siloxane-based macrodiol, a modified hard segment, an aromatic polyurethane, is a variation of Elast-Eon ™ 2 with further improved flexibility due to the introduction of siloxane into the hard segment. Elast-Eon ™ 4 is a modified aromatic hard segment polyurethane.

Bayer Corporation also produces candidate materials. Texin 4210 and Texin 4215 are thermoplastic polyurethane / polycarbonate mixtures for injection molding and extrusion. Texin 5250 , 5286 and 5290 are medical materials for injection molding and extrusion based on polyether with a Shore D hardness of about 50, 86 and 90 respectively.

In some embodiments, the prosthetic device is a melt-molded one Composite implant composed of two biocompatible materials: DSM Bionate® polycarbonate-urethane (PCU), 80 Shore A. , a matrix material and ultra high molecular weight polyethylene (UHMWPE) reinforcement material (Dyneema purity). In some particular embodiments, a prosthetic device formed from PCU and circumferentially reinforced with DSM Dyneema® fibers results in a desirable distribution of loads on the articular surfaces underlying the prosthetic device.

It is now on the 8th Referring to Figure 1, a top view of a knee joint with an injured meniscus 10 is shown. The meniscus includes an outer rim 15th that is attached to the bone along the posterior margin 20th and the anterior margin 22nd is anchored. With reference to the 8th the torn segments were removed along with the undamaged central meniscus to expose the underlying tibia and an implantation area 30th define. The implantation area 30th is through the side wall 21st limited. A prosthetic meniscal device 110 according to one aspect of the present disclosure is in the meniscal pocket 30th positioned by the side wall 21st is limited. As will be discussed in greater detail below, the prosthetic meniscus engages an artificial femoral bearing component to hold the meniscus device in place A. , B. and C. inside the meniscus pocket 30th to move. The positions A. , B. and C. be offset from one another in the longitudinal direction, rotationally and / or laterally.

Referring to the 9A-9C , there is an artificial femur support component (FBC) 120 shown being on a femur F. implanted, and a prosthetic meniscus device (PMD) 110 placed between the femur support component and the natural tibial head of the tibia. T is located. When the axis of the femur FA with the axis of the tibia TA is aligned, a first support section of the FBC engages the PMD and the PMD is in a first position A. located in relation to the shin. The position of the PMD 110 may be characterized by a top-down axis MP that extends through the center of the PMD. In the position A. is the PMD by a distance D1 offset with respect to the tibial axis TA arranged. The distance D1 describes the separation between the axis MP of the PMD and the tibial axis TA . 10A illustrates the view from the tibia T in position A. and shows the rotational orientation of the PMD sidewall 114 with respect to the anterior-posterior axis AP as well as the orientation of the PMD 110 to the axis FB extending from the anterior side to the posterior side of the FBC 120 extends. In the position A. is the angle between the edge of the PMD 120 and the axis AP β .

Referring to the 9B and 10B , these figures illustrate the movement of PMD when the femur F. up to the position of the angle α ' between the axis FA and the axis TA is moved. The PMD is now in engagement with a second support surface of the FBC, which has a different radius of curvature. As a result of this contact, the PMD 110 moved posteriorly and is now at a distance D1 ' off the axis TA that is greater than D1 is. In addition, the PMD 110 clockwise with respect to the axis AP to the smaller angle β ' turned. The relationship shown is the position B. . The PMD 110 has moved longitudinally, rotationally and / or laterally between positions A. and B. emotional. A shift in PMD 110 along the axis AP can be described as a longitudinal movement. A shift in PMD 110 along a medial-lateral axis perpendicular to the axis AP can be described as a lateral movement.

Referring to the 9C and 10C , continued rotation of the thighbone with respect to the tibia results in an angle α ' 'which is greater than the angle α ' and is almost 90 degrees. The PMD is now in engagement with a third support surface of the FBC with a different radius of curvature. As a result of this contact, the PMD 110 moved posteriorly and is now at a distance D1 '' off the axis TA that is greater than D1 ' is. In addition, the PMD 110 clockwise with respect to the axis AP at a smaller angle β '' rotated, which is now a negative angle relative to the AP axis. The relationship shown is the position C. . The PMD 110 has moved longitudinally, rotationally and / or laterally between positions B. and C. as well as the positions A. and B. emotional.

While the foregoing is not limiting, the total displacement distance D1 the PMD range from 3-20 mm in the anterior to the posterior plane, in one embodiment D1 5 mm, D1 ' 10 mm and D1 '' 15 mm. Similarly, but not limited to, the PMD rotation angle can range from 3 to 30 degrees over the entire angular rotation. In the 10A-10C embodiment shown is β about 10 degrees, β ' is about 5 degrees and β '' is approximately -5 degrees relative to the AP line. Although the angles are shown relative to the AP line, the sidewall changes 114 also by the same angular amounts relative to the axis FB of the FBC 120 .

As above in relation to the 9A-10C is shown when the first, the second and the third area of the FBC engage in the PMD, the PMD floats on the natural tibial head and shifts into the positions shown while rotating at the same time. In one embodiment, the first support surface of the FBC engages in a first meniscus support surface on the PMD in order to support the device 110 in the position A. while a second bearing surface on the FBC engages a second meniscus bearing surface on the PMD to keep the device in place B. to force while a third pad on the FBC engages a third meniscus pad on the PMD to keep the device in place C. to force.

Referring to the 11A and 11B , There is another embodiment of a meniscus replacement device 460 shown in accordance with another aspect of the present disclosure. The implant 460 includes straps 450 , 454 , 456 and 458 . How more comprehensive in the U.S. application 14 / 212,330 , filed March 14, 2014, entitled "Meniscus Prosthetic Devices with Anti-Migration or Radiopaque Features," the loops are formed by a series of fibers loosely wrapped around a core after the tension members are positioned, wherein slack portions are held outward during the overflow molding process to form the loops. Thus, in one embodiment, the loops 450 , 454 , 456 and 458 formed from a series of filaments that are partially embedded in the overmolded area and partially extend beyond the side walls. The loops themselves can also comprise a coating of the overmolding material. In one embodiment, each loop has a specific set of filaments that extend around the core so that when a loop is cut, the severing of the fibers does not affect the remaining loops. In yet another embodiment, one or more fiber-reinforced tabs extend outward from the outer side wall. Although the tabs do not have a preformed opening, the tabs provide fiber reinforced areas for a needle and suture to pass through that can hold the suture in place without damaging the pliable material of the implant. In one aspect, the tabs around the implant are spaced apart at strategic locations, while in another embodiment the fiber-reinforced tab extends completely around the sidewall circumference of the implant.

When the implant 460 used, it can be used after the femur support component is implanted 120 be introduced into the joint space. In one aspect, it is the anterior tether 458 adjacent to the anterior margin 22nd positioned and a suture 470 is through the loop 458 and the anterior margin 22nd guided. The tension applied to the suture can be varied to provide the appropriate freedom of movement within the joint space. The other unused straps can be cut by the doctor before implantation in the joint space. In an alternative arrangement, the implant 460 positioned in the space that is within the remaining sections of the meniscus 15th is formed, the strap 456 next to the posterior margin 20th is positioned. A suture is put through the loop 456 and the posterior margin 20th guided to hold the implant within the joint space. In the two holding arrangements described, the implant 460 has a high degree of freedom of movement in the joint space so that the implant retains its ability to float freely within the joint to simulate a natural meniscus. In yet another aspect, the one or more tether straps are 454 , 456 and 458 attached to the soft tissue of the joint capsule.

Referring to 11B , the implant 460 is held in the joint space even better by a suture material that runs through all or part of the retaining loops 454 , 456 and 458 and around the meniscus margin 15th extending around the posterior margin 20th and the anterior margin 22nd includes. The implant is in this arrangement 460 held in a smaller range of motion which determines motion over a limited range, although anterior to posterior translation and rotation relative to the tibial head is allowed.

It is now on the 12A-13C Reference which is shown in another embodiment of a partial unicompartmental knee replacement system in accordance with another aspect of the present disclosure. The PUKR 1200 includes a prosthetic meniscus device (PMD) 1210 and an artificial tibial support component 1220 . Here is the PMD 1210 located between and in contact with the artificial tibia support component 1220 and the natural femur support surface. The upper surface of the PMD 1210 is basically shaped as described above with a meniscus support surface which is configured in such a way that it engages in a first, a second and a third support surface of the thigh bone. As also described above, the first, second and third bearing surfaces of the natural femur can each have a first, second and third radius of curvature. The lower surface of the PMD 1210 is shaped to work with the TBC 1220 get engaged and the PMD through move a variety of positions as explained below.

As in the 14A-15C As shown, the tibial support component includes a keel 1240 with a height H1 for positioning in a bone canal in the tibia to anchor the device in a stationary position with respect to the tibia. The TBC includes a medial sidewall 1228 and a tip 1224 that is the maximum height H2 Are defined. The TBC has a maximum width W and a length L. . In one embodiment, H1 is approximately 8 mm, H2 is approximately 14 mm, W is approximately 31 mm and L. about 49 mm. A support surface 1226 extends between the side walls 1228 and 1230 and the end walls 1232 and 1234 . The supporting surface 1226 includes a convex region adjacent to the apex 1224 .

Referring now to the 16A-17C , there is shown a series of angular positions of the femur with respect to the tibia and the corresponding movement of the PUKR system in the knee joint. In the 16A the femur axis FA is essentially with the tibia axis TA aligned. In this position A. is the posterior wall 1212 the PMD 1210 essentially with the posterior wall 1250 the TBC 1220 aligned. When the axis of the femur FA with the axis of the tibia TA is aligned, a first support section of the TBC engages the PMD and the PMD is in a first position A. positioned relative to the tibia. 17A Figure 3 illustrates the view of the femur in position A. and shows the rotational orientation of the PMD with respect to the sidewall 1228 the TBC passing through the line TP as well as the orientation of the PMD relative to the tibia. The line TP represents an anterior-posterior axis along the sidewall 1228 the TBC 1220 . In the position A. is the angle between the medial edge of the PMD 1210 and the line TP A. .

With reference to the 16B and 17B , these figures show the the movement of the PMD when the femur F. is moved to the position where the angle α ' between the axis FA and the axis TA amounts. The PMD 1210 is now in engagement with a second bearing surface of the natural thigh bone, which has a different radius of curvature, which causes the PMD in the TBC bearing surface 1226 intervenes, causing the PMD to shift and rotate, as in the 16B and 17B is shown. As a result of this contact, the PMD 110 displaced posteriorly and their posterior wall 1212 now has a gap D2 ' from the posterior wall 1250 the TBC 1220 . In addition, the PMD 1210 clockwise with respect to the line TP up to the smaller angle A ' turned. The relationship shown describes the position B. . The PMD 110 has moved longitudinally, rotationally and / or laterally between positions A. and B. emotional.

With reference to the 16C and 17C Continued rotation of the femur relative to the tibia results in an angle α ' 'which is greater than the angle α ' . The PMD is now in engagement with a third bearing surface of the natural femur with a different radius of curvature and a different section of the TBC bearing surface 1226 . Through this contact, the PMD 110 moved posteriorly and is now at a distance D2 " from the posterior surface 1250 that is greater than D2 ' is. In addition, the PMD 110 clockwise relative to the side wall 1228 the TBC turned that through the line TP is shown at a smaller angle A '' which is now a negative angle relative to the TP line. The relationship shown describes the position C. . The PMD 110 has moved longitudinally, rotationally and / or laterally between positions B. and C. as well as the positions A. and B. emotional.

16D illustrates continued rotation of the femur relative to the tibia up to an angle α ' '', which is essentially 90 degrees, to a further shift up to a distance D2 ''' leads that is greater than D2 ' 'is.

Although the foregoing is not limiting, the total shift distance D2 the PMD range from 3-20 mm in the anterior to the posterior plane, in one embodiment D2 ' 3 mm, D2 ' '7 mm and D2 ''' 14 mm. Similarly, but not limited to, the PMD rotation angle can range from 3 to 30 degrees over the entire angular rotation. In the 10A-10C embodiment shown is the angle A. about 10 degrees, the angle A ' is about 3 degrees and the angle A '' is approximately -10 degrees relative to the AP line.

Although the composite implants described above are described in the context of a partial unicompartmental knee replacement system, they can be used to form a variety of prosthetic devices. For example, in some instances, the composite implants are used for knee joints (including meniscus and total knee joints), hip joints (including acetabular cups), shoulder joints, elbow joints, finger joints, and other load and / or non-load bearing prosthetic devices.

It should be understood that, in some instances, the prosthetic devices of the present disclosure may be formed by processes other than those described herein. These manufacturing methods include any suitable manufacturing method. For example, any of the following manufacturing methods may be used without, but are not limited to: injection molding with insertion of inserts; Compression molds with insertion of inserts; Injection molds with inserting inserts; Compression molding of prefabricated elements preformed by any of the above methods including inserting inserts; Spraying with insertion of inserts; Immersion with insertion of inserts; Machining of sticks or bars; Processing of prefabricated elements with insertion of inserts; and / or one of the above methods without inserts. Further, it should be understood that, in some embodiments, the prosthetic devices of the present disclosure are formed from medical grade materials other than those specifically identified above. Thus, in some embodiments, the prosthetic devices are formed from any suitable medical grade material.

While the principles of the present disclosure have been set forth using the specific embodiments discussed above, no limitations are intended to be implied. Any and all changes or modifications to the devices, instruments and / or methods described, as well as any further application of the principles of the present disclosure that would be obvious to a person skilled in the art, are embraced by the present disclosure, even if they are not expressly discussed herein. It is also recognized that various presently unforeseen or unexpected alternatives, modifications, and variations of the present disclosure can hereinafter be made by those skilled in the art. All such variations, modifications, and improvements as would be obvious to one skilled in the art to which this disclosure pertains are included in the following claims.

• [Aspekt 1] Partielles unikompartimentelles Knieersatzsystem zur Implantation zwischen einem Oberschenkelknochen und einem Schienbein eines Patienten, umfassend:
  • eine Oberschenkelknochen-Komponente, die dazu ausgebildet ist, wenigstens einen Bereich einer Oberschenkelkondyle wiederherzustellen, wobei die Oberschenkelknochen-Komponente einen ersten Bereich mit einem ersten Krümmungsradius, einen zweiten Bereich mit einem zweiten Krümmungsradius aufweist, und einen dritten Bereich mit einem dritten Krümmungsradius aufweist; und
  • eine Meniskus-Komponente, die dazu ausgebildet ist, zwischen der Oberschenkelknochen-Komponente und dem natürlichen Schienbein positioniert zu werden, wobei die Meniskus-Komponente im Kniegelenk zwischen dem Schienbein und der Oberschenkelknochen-Komponente schwimmt und eine erste Position in dem Kniegelenk einnimmt, wenn sie mit dem ersten Bereich in Kontakt steht, eine zweite Position in dem Kniegelenk einnimmt, wenn sie mit dem zweiten Bereich in Kontakt steht, und eine dritte Position in dem Kniegelenk einnimmt, wenn sie mit dem dritten Bereich in Kontakt steht.
• [Aspekt 2] System nach Aspekt 1, wobei die erste Position bezüglich der zweiten und/oder dritten Positionen in Drehrichtung versetzt ist.
• [Aspekt 3] System nach Aspekt 1 oder 2, wobei die erste Position in Längsrichtung bezüglich der zweiten und/oder dritten Positionen versetzt ist.
• [Aspekt 4] System nach einem vorhergehenden Aspekt, wobei die erste Position seitlich bezüglich der zweiten und/oder dritten Position versetzt ist.
• [Aspekt 5] System nach einem vorhergehenden Aspekt, wobei die Drehung der Meniskus-Komponente größer als 2,5 Grad ist.
• [Aspekt 6] System nach einem vorhergehenden Aspekt, wobei die Verschiebung der Meniskus-Komponente größer als 5 mm ist.
• [Aspekt 7] System nach einem vorhergehenden Aspekt, wobei die Meniskus-Komponente lose an Weichgewebe neben dem Kniegelenk befestigt ist.
• [Aspekt 8] System nach einem vorhergehenden Aspekt, wobei zumindest der erste Krümmungsradius von dem dritten Krümmungsradius verschieden ist.
• [Aspekt 9] System nach Aspekt 5, wobei die Verschiebung der Meniskus-Komponente größer als 5 mm ist.
• [Aspekt 10] Partielles unikompartimentelles Knieersatzsystem zur Implantation zwischen einem Oberschenkelknochen und einem Schienbein eines Patienten, umfassend:
  • eine Oberschenkelknochen-Komponente mit mindestens drei Kontaktbereichen mit jeweils unterschiedlichem Krümmungsradius; und
  • eine Meniskus-Komponente mit einer oberen Kontaktfläche zum Eingriff mit der Oberschenkelknochen-Komponente, wobei die obere Kontaktfläche eine Mehrzahl von Radien zur Kontaktierung der Oberschenkelknochen-Kontaktbereiche aufweist, und mit einer untere Schienbein-Kontaktfläche zum Eingriff mit einer Knorpelauflagefläche des Schienbeins aufweist, wobei die Meniskus-Komponente relativ zu der Schienbein-Komponente durch wenigstens eine erste Position und eine zweite Position schwimmt basierend auf dem Kontakt zwischen den Oberschenkelknochen-Kontaktbereichen und der oberen Kontaktfläche, wobei die erste Position relativ zu der zweiten Position wenigstens rotationsversetzt ist.
• [Aspekt 11] Partielles unikompartimentelles Knieersatzsystem zur Implantation zwischen einem Oberschenkelknochen und einem Schienbein eines Patienten, wobei das System umfasst:
  • eine Schienbein-Auflagekomponente mit einer Verankerungsfläche zur gesicherten Befestigung am Schienbeinknochen und einer gegenüberliegenden Auflagefläche mit einer mittigen konvexen Oberfläche benachbart zu einer medialen Seitenwand;
  • eine flexible Meniskus-Komponente mit einer Oberschenkelknochen-Auflagefläche, die ausgebildet ist, mit der Knorpelauflagefläche am Oberschenkelknochen ein Gelenk zu bilden, und mit einer gegenüberliegenden Auflagefläche für das Schienbein, die dazu ausgebildet ist, selektiv mit der Schienbein-Auflagefläche zusammenzuwirken, so dass in einer ersten Position relativ zu der Schienbein-Auflagekomponente die Meniskus-Komponente dazu ausgebildet ist, eine erste Winkelposition relativ zu der medialen Seitenwand einzunehmen, und in einer zweiten Position relativ zu der Schienbein-Auflagekomponente, die bezüglich der ersten Position nach posterior verschoben ist, die Meniskus-Komponente dazu ausgebildet ist, eine zweite Winkelposition relativ zu der medialen Seitenwand einzunehmen, wobei die zweite Position sich von der ersten Position unterscheidet.
• [Aspekt 12] System nach Aspekt 11, wobei die Drehung der Meniskus-Komponente zwischen der ersten und der zweiten Winkelposition größer als 3 Grad ist.
• [Aspekt 13] System nach Aspekt 11 oder 12, wobei die Verschiebung der Meniskus-Komponente zwischen der ersten und der zweiten Position größer als 3 mm ist.
• [Aspekt 14] System nach einem der Aspekte 11 bis 13, wobei die Meniskus-Komponente eine dritte Position relativ zu der Schienbein-Auflagekomponente einnehmen kann, wobei die dritte Position bezüglich der ersten und/oder zweiten Position nach posterior verschoben ist, und wobei in der dritten Position die Meniskus-Komponente eine dritte Winkelposition relativ zu der medialen Seitenwand einnimmt, wobei die dritte Position von der ersten und/oder zweiten Position verschieden ist.
• [Aspekt 15] Verfahren zum Einsetzen eines unikompartimentellen Knieersatzsystems zwischen einem Oberschenkelknochen und einem Schienbein eines Patienten, wobei das Verfahren umfasst:
  • Implantieren einer Oberschenkel-Komponente mit mindestens zwei unterschiedlichen Radien entlang ihrer Kontaktfläche auf eine Oberschenkelkondyle; und
  • Einsetzen einer Meniskus-Komponente zwischen das Schienbein und die Oberschenkelknochen-Komponente, wobei die Meniskus-Komponente durch Eingriff zwischen der Oberschenkelknochen-Komponente und der natürlichen Schienbein-Auflagefläche gehalten ist.
• [Aspekt 16] Verfahren nach Aspekt 15, wobei das Einsetzen einer Meniskus-Komponente umfasst:
  • Positionieren der Meniskus-Komponente zwischen dem Schienbein und der Oberschenkelknochen-Komponente, so dass die Meniskus-Komponente zwischen der Oberschenkelknochen-Komponente und der natürlichen Schienbein-Auflagefläche schwimmt.
• [Aspekt 17] Verfahren nach Aspekt 15 oder 16, wobei das Einsetzen einer Meniskus-Komponente umfasst:
  • Positionieren der Meniskus-Komponente zwischen dem Schienbein und der Oberschenkelknochen-Komponente, so dass die Meniskus-Komponente eine erste Position aufweist, wenn sie in Kontakt mit einem ersten Bereich der Oberschenkelknochen-Komponente mit einem ersten Krümmungsradius steht, und eine zweite Position, wenn sie in Kontakt mit einem zweiten Bereich der Oberschenkelknochen-Komponente mit einem zweiten Krümmungsradius steht.
• [Aspekt 18] Verfahren nach Aspekt 17, wobei die erste Position und die zweite Position zueinander in Drehrichtung versetzt, in Längsrichtung versetzt und/oder in seitlicher Richtung versetzt sind.
• [Aspekt 19] Verfahren nach Aspekt 17 oder 18, wobei die Meniskus-Komponente eine dritte Position einnimmt, wenn sie in Kontakt mit einem dritten Bereich der Oberschenkelknochen-Komponente mit einem dritten Krümmungsradius steht, und wobei die dritte Position bezüglich der ersten und/oder zweiten Position in Drehrichtung versetzt, in Längsrichtung versetzt und/oder in seitlicher Richtung versetzt ist.

Advantageous aspects of the present disclosure can be formulated as follows:

• [Aspect 1] A partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, comprising:
  • a femur component configured to restore at least a portion of a femoral condyle, the femur component having a first region with a first radius of curvature, a second region with a second radius of curvature, and a third region with a third radius of curvature; and
  • a meniscus component adapted to be positioned between the femur component and the natural tibia, the meniscus component floating in the knee joint between the tibia and the femur component and assuming a first position in the knee joint when it is is in contact with the first area, assumes a second position in the knee joint when it is in contact with the second area, and assumes a third position in the knee joint when it is in contact with the third area.
• [Aspect 2] System by aspect 1 , the first position being offset in the direction of rotation with respect to the second and / or third positions.
• [Aspect 3] System by aspect 1 or 2 wherein the first position is offset in the longitudinal direction with respect to the second and / or third positions.
• [Aspect 4] System according to any preceding aspect, wherein the first position is laterally offset with respect to the second and / or third position.
• [Aspect 5] The system according to any preceding aspect, wherein the rotation of the meniscus component is greater than 2.5 degrees.
• [Aspect 6] The system according to any preceding aspect, wherein the displacement of the meniscus component is greater than 5 mm.
• [Aspect 7] The system of any preceding aspect, wherein the meniscus component is loosely attached to soft tissue adjacent to the knee joint.
• [Aspect 8] The system according to any preceding aspect, wherein at least the first radius of curvature is different from the third radius of curvature.
• [Aspect 9] System by aspect 5 where the displacement of the meniscus component is greater than 5 mm.
• [Aspect 10] A partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, comprising:
  • a femur component with at least three contact areas each with a different radius of curvature; and
  • a meniscus component having an upper contact surface for engagement with the Femur component, wherein the upper contact surface has a plurality of radii for contacting the femur contact areas, and having a lower tibial contact surface for engagement with a cartilage support surface of the tibia, wherein the meniscus component relative to the tibia component by at least one first position and a second position floats based on the contact between the femur contact areas and the upper contact surface, the first position being at least rotationally offset relative to the second position.
• [Aspect 11] A partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, the system comprising:
  • a tibial support component having an anchoring surface for secure attachment to the tibia and an opposing support surface having a central convex surface adjacent a medial sidewall;
  • a flexible meniscus component having a femur support surface that is configured to articulate the cartilage support surface on the femur and an opposing support surface for the tibia that is configured to selectively cooperate with the tibia support surface so that in in a first position relative to the tibial support component, the meniscus component is configured to assume a first angular position relative to the medial sidewall, and in a second position relative to the tibial support component which is displaced posteriorly with respect to the first position, the Meniscus component is configured to assume a second angular position relative to the medial sidewall, the second position being different from the first position.
• [Aspect 12] System by aspect 11 wherein the rotation of the meniscus component between the first and second angular positions is greater than 3 degrees.
• [Aspect 13] System by aspect 11 or 12 wherein the displacement of the meniscus component between the first and second positions is greater than 3 mm.
• [Aspect 14] System according to one of the aspects 11 to 13 wherein the meniscus component can assume a third position relative to the tibia support component, the third position being displaced posteriorly with respect to the first and / or second position, and wherein in the third position the meniscus component has a third angular position relative to of the medial sidewall, wherein the third position is different from the first and / or second position.
• [Aspect 15] A method of deploying a unicompartmental knee replacement system between a femur and a shin of a patient, the method comprising:
  • Implanting a femoral component with at least two different radii along its contact surface onto a femoral condyle; and
  • Inserting a meniscus component between the tibia and the femur component, the meniscus component being held by engagement between the femur component and the natural tibia bearing surface.
• [Aspect 16] Method according to aspect 15th wherein deploying a meniscus component comprises:
  • Positioning the meniscus component between the tibia and the femur component so that the meniscus component floats between the femur component and the natural tibial bearing surface.
• [Aspect 17] Method according to aspect 15th or 16 wherein deploying a meniscus component comprises:
  • Positioning the meniscus component between the tibia and the femur component so that the meniscus component has a first position when in contact with a first portion of the femur component having a first radius of curvature and a second position when it is is in contact with a second portion of the femur component having a second radius of curvature.
• [Aspect 18] Method according to aspect 17th , the first position and the second position being offset from one another in the direction of rotation, offset in the longitudinal direction and / or offset in the lateral direction.
• [Aspect 19] Method according to aspect 17th or 18th wherein the meniscus component assumes a third position when in contact with a third area of the femur component with a third Radius of curvature stands, and wherein the third position is offset in the direction of rotation with respect to the first and / or second position, offset in the longitudinal direction and / or offset in the lateral direction.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 8361147 [0010]
• US 14212330 [0044]

Claims (27)

A partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, comprising: a femur component (120) configured to restore at least a portion of a femoral condyle, the femur component having a first portion (310) with a first Having a radius of curvature and a second region (312) with a second radius of curvature, characterized in that the femur component further comprises a third region (314) with a third radius of curvature and in that the system further comprises: a meniscus component (110) which is designed to be positioned between the femur component (120) and the natural tibia, the meniscus component (110) floating in the knee joint between the tibia and the femur component (120) and having a first position in the knee joint when you mi t is in contact with the first region (310), has a second position in the knee joint when it is in contact with the second region (312), and has a third position in the knee joint when it is in contact with the third region (314) is in contact. System according to Claim 1 , the first position being offset in the direction of rotation with respect to the second and / or third position. System according to Claim 1 or 2 , wherein the first position is offset in the longitudinal direction with respect to the second and / or third position. System according to one of the preceding claims, wherein the first position is laterally offset with respect to the second and / or third position. The system of any preceding claim, wherein the rotation of the meniscus component (110) is greater than 2.5 degrees. A system according to any preceding claim, wherein the displacement of the meniscus component (110) is greater than 5 mm. The system of any preceding claim, wherein the meniscus component (110) is loosely attached to soft tissue adjacent the knee joint. A system according to any preceding claim, wherein at least the first radius of curvature is different from the third radius of curvature. System according to one of the Claims 5 to 8th wherein the displacement of the meniscus component (110) is greater than 5 mm. A partial unicompartmental knee replacement system for implantation between a femur and a shin of a patient, the system comprising: a tibial support component (1220) having an anchoring surface for secure attachment to the tibia and an opposing support surface (1226) having a central convex surface adjacent a medial sidewall (1228); a flexible meniscus component (1210) having a femur support surface configured to articulate the cartilage support surface on the femur and an opposing tibial support surface adapted to be selectively connected to the tibia support surface (1226 ) cooperate, so that in a first position relative to the tibial support component (1220) the meniscus component (1210) is configured to assume a first angular position relative to the medial side wall (1228), and in a second position relative to the Tibial support component (1220) displaced posteriorly with respect to the first position, the meniscus component (1210) being configured to assume a second angular position relative to the medial sidewall (1228), the second position extending from the first position differs. System according to Claim 10 wherein the rotation of the meniscus component (1210) between the first and second angular positions is greater than 3 degrees. System according to Claim 10 or 11 wherein the displacement of the meniscus component (1210) between the first and second positions is greater than 3 mm. System according to one of the Claims 10 to 12 wherein the meniscus component (1210) has a third position relative to the tibia support component (1220), wherein the third position is displaced posteriorly with respect to the first and / or second position, and wherein in the third position the meniscus component (1210) assumes a third angular position relative to the medial sidewall (1228), the third position being different from the first and / or second position. A partial unicompartmental knee replacement system for implantation between a femur and a tibia in a knee joint, the system comprising: means for replacing a natural femur support surface of the Thighbone, wherein the means has a bearing surface which is designed to simulate a shape of the natural femur bearing surface; and a meniscus prosthesis configured to replace a natural meniscus, the meniscal prosthesis comprising an upper support surface for engagement with the means, a lower support surface for direct engagement with a native tibial head of the tibia, an outer body portion and a central body portion, the outer body portion has an increased thickness relative to the central body portion so that the outer body portion is dimensioned and shaped to prevent undesired popping out of the meniscal prosthesis from the knee joint, the meniscus prosthesis being designed to be positioned between the femur and the tibia in the knee joint without any attachment to hold the meniscal prosthesis in place, so that when the knee is flexed in the knee joint, the meniscal prosthesis floats between the thighbone and the shinbone, the meniscal prosthesis being designed to with the Means cooperating to move through a plurality of positions as the knee joint moves through a plurality of angles during flexion of the knee, the plurality of positions including at least a first position and a second position, and wherein in the second position the meniscus prosthesis is displaced posteriorly and offset in the direction of rotation with respect to the first position. System according to Claim 14 wherein the first position is laterally offset with respect to the second position. System according to Claim 14 or 15th , wherein the bearing surface of the means comprises a first portion with a first radius of curvature and a second portion with a second radius of curvature, wherein in the first position of the plurality of positions, the upper bearing surface of the meniscus prosthesis is designed with the first portion of the bearing surface with the first Radius of curvature to be in contact, and wherein in the second position of the plurality of positions, the upper bearing surface of the meniscus prosthesis is configured to be in contact with the second portion of the bearing surface having the second radius of curvature. System according to one of the Claims 14 to 16 wherein the plurality of translational rotary positions further comprise a third position, and wherein in the third position the flexible meniscus prosthesis is displaced further posteriorly and offset in the direction of rotation with respect to the second position. System according to Claim 17 , wherein the bearing surface of the means comprises a first portion with a first radius of curvature and a second portion with a second radius of curvature, wherein in the first position of the plurality of positions, the upper bearing surface of the meniscus prosthesis is designed with the first portion of the bearing surface with the first Radius of curvature to be in contact, wherein in the second position of the plurality of positions, the upper bearing surface of the meniscus prosthesis is designed to be in contact with the second portion of the bearing surface with the second radius of curvature, wherein in the third position of the plurality of positions the upper The bearing surface of the meniscus prosthesis is designed to be in contact with the third section of the bearing surface with the third radius of curvature. System according to one of the Claims 14 to 18th where the rotation of the meniscus component is between 3 degrees and 30 degrees. System according to one of the Claims 14 to 19th , the displacement of the meniscus component being between 3 mm and 20 mm. System according to one of the Claims 14 to 20th wherein a medial-lateral dimension of the means is smaller than a corresponding medial-lateral dimension of the meniscus prosthesis. System according to one of the Claims 14 to 21st wherein the means is adapted to replace a small defect in a natural femur abutment, the means comprising a single pin adapted to hold the means within the knee joint. System according to Claim 22 with the single pin centered relative to the contact surface of the means. System according to Claim 22 or 23 wherein the single pin extends perpendicularly relative to the contact surface of the means. System according to one of the Claims 14 to 24 wherein the means comprises two pins adapted to hold the means within the knee joint. System according to one of the Claims 14 to 25th wherein the agent comprises a biocompatible material. System according to Claim 26 wherein the agent comprises cobalt chrome.

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